1. Field of the Invention
This invention relates generally to a self-adhesive laminate and a method for using this laminate for sealing window frames.
2. Description of the Related Art
In building construction, prefabricated windows are supplied with a metal flange along their perimeter. This flange is nailed to the building sub-siding. The finish siding is then applied over the flange. The flange is not tightly sealed to the sub-siding and wind-driven rain can cause water leaks around the flange. These leaks can be prevented if a layer of tape is applied to seal the joint between the flange and sub-siding.
Various types of adhesive tapes or laminates have been used to seal these flanges. These laminates generally are dark-colored and comprise a polyethylene film adhered to a bitumen layer. However, the use of such a tape has several disadvantages.
First, due to the dark color of the tape, exposure to sunlight causes it to become heated above ambient temperatures. This can cause difficulty in application of the tape and creates problems with adequate adhesion at higher temperatures, causing the seal formed upon application of the tape to deteriorate. Even if a light-colored polyethylene is used, the tape still absorbs sufficient heat to adversely affect adhesion.
Second, polyethylene film is easily stretched. If the tape is overstretched, it will tend to contract over time and pull away from the underlying flange. This too creates a deterioration in the seal.
Finally, the polyethylene absorbs oils present in many adhesive compounds. This causes the polyethylene to swell and wrinkle, also causing a breakdown in the seal formed.
Some prior art adhesive laminates include a variety of layers. However, these laminates are not feasible for use in the present application. First, these products are designed to be used on roofing. Roofing uses require a greater degree of strength, due to the nature of their function and the long exposure to the elements of nature. The roofing membranes currently used are also significantly thicker and less flexible than the self-adhesive laminate disclosed herein. Use of such roofing membranes for sealing window frames would be economically impractical due to significantly increased material cost in making the laminate and the increased labor in applying the laminate, due to its stiffness relative to the present invention. Examples of such laminates are shown in the U.S. patents to Tajima et al., U.S. Pat. Nos. 3,937,640 and 4,055,453; Yamamoto, U.S. Pat. No. 4,374,687; Clapperton, U.S. Pat. No. 4,386,981; Crepeau, U.S. Pat. No. 4,514,442; Paeglis et al., U.S. Pat. No. 4,589,804; Cooper et al., U.S. Pat. No. 4,670,071; and Simpson et al., U.S. Pat. No. 5,096,759.
The present invention solves these and other problems present in the prior art by providing a number of features. First, the present invention uses a sheet of transparent or translucent material with a low degree of elasticity, the latter feature tending to prevent overstretching. Next, the present invention incorporates a reflective layer to prevent the overheating of the laminate. Finally, the present invention places the reflective layer between the translucent or transparent sheet of material and the adhesive to prevent oils from migrating from the adhesive and into the sheet of material. In these ways, the present invention is a significant improvement over the prior art.
The present invention relates to a self-adhesive laminate for sealing window frames. The laminate includes a polyester layer, an aluminum layer, an adhesive layer, and preferably a removable paper or plastic layer overlying the adhesive layer. The removable layer is referred to herein as a release layer.
The aluminum layer has a first side and an opposing second side. The polyester layer is adhered to the first side of the aluminum layer. The adhesive layer is applied to the second side of the aluminum layer. The release layer overlies the adhesive remote from the aluminum layer.
The aluminum layer preferably is between about 10 nm and about 100 nm thick. The polyester layer is preferably transparent or translucent and is between about 0.00045 in. and about 0.002 in. thick. The adhesive layer is preferably pressure-sensitive and is between about 0.015 in. and about 0.060 in. thick. The aluminum and polyester are preferably adhered to one another by depositing the aluminum layer on the polyester layer by vapor deposition.
The adhesive is preferably based on rubberized asphalt, butyl rubber, or polyisobutylene. The adhesive is most preferably a rubberized asphalt comprising asphalt, thermoplastic elastomers, process oil, and tackifying resins.